Not much going on these days, huh? There are only a few things on the president’s — and Congress’ — plate, including:

Guns

A big budget compromise

Immigration overhaul

North Korea

Bombs at the Boston Marathon

Iran’s nuclear program

And oh yes, jobs and the economy

Recent events once again prove that while politicians — and particularly presidents — like to believe that they can always set the agenda, much of political leadership involves responding to circumstances.

“Stuff happens” is the way I like to put it. It can be an oil spill, a shooting, a foreign leader firing on his own citizens, a trial of a doctor who killed women and children at an abortion clinic or some crisis manufactured by a largely unknown young political leader who needs to solidify himself at home.

President Barack Obama’s gun control initiative certainly looks like a loser, with the most ardent supporters now looking for a way to spin the defeat of the compromise on background checks led by Patrick J. Toomey and Joe Manchin III. The compromise probably wouldn’t upset the National Rifle Association all that much (though you’ll never hear it from leaders of that group).

Three months ago, supporters of stronger gun control figured a significant legislative response to the Newtown, Conn., shooting was likely. Now any expansion of current restrictions would be seen as a victory — or at least as something better than a shutout.

A big budget compromise doesn’t look particularly near now, even with the president’s offer to change the way the cost-of-living adjustment for Social Security is measured. The Democratic left, sounding much like the Republican right, rules out any significant compromise by the president, and even some Republicans who should embrace Obama’s offer suddenly have cold feet about angering seniors.

But immigration does look like a place where a deal is likely, something that many of us thought was likely shortly after the exit polls on election night shocked GOP members of Congress and party strategists. Still, the devil is always in the details, and there will be plenty of opportunities for opponents to stop a deal.

Interestingly, immigration is the one place where the president has gotten out of the way and allowed key members of Congress to fashion a deal that neither side loves but both sides feel is acceptable. This is one policy area where the adults on Capitol Hill seem to be in charge.

Then there are foreign policy issues and concerns, from North Korea and Iran to Syria (and maybe even the health of the European Union), all of which the president probably would prefer to ignore as he seeks to establish his legacy on domestic policy. But events around the globe seem to have a mind of their own, distracting our leaders from other issues that need full attention.

The Boston tragedy certainly brings with it plenty of unknowns, and a multitude of ramifications depending on the details about the “who,” the “what” and the “why.”

The question is whether the White House can juggle all of these concerns and problems … and whether there are more unexpected, unsettling developments that will draw the attention of the administration and congressional leaders in the days ahead.